The use of gang slats for slotted floor sections in animal shelters of the farrowing house type has been well accepted by the swine production industry. As is known to those familiar with the applicable arts, in a typical farrowing house utilizing contemporary gang slats for the flooring thereof, each such gang slat supports a farrowing crate thereon having a central pen for confining a sow therein and side pens extending along opposite sides of the central pen for accommodating a litter of pigs. The litter has access to the sow for feeding by passing under a divider extending between the central pen and each side pen. Generally, the farrowing crates and respective gang slats are arranged in side-by-side relation in each of two rows, with a center aisle between the rows providing access to the front portions of the farrowing crates.
The gang slats are supported at opposite ends on the peripheral and central walls of the farrowing house in spaced relation to, and above, the ground surface to form a pit beneath the flooring, and each gang slat has a plurality of slots therein for passage therethrough of waste from the sow and the litter of pigs in the respective farrowing crate to the pit therebelow. The slotted gang slats thus reduce cleaning and also greatly retard the spread of disease and parasites by allowing removal of excrement from the farrowing crates. Also, the slotted floor formed of the gang slats is an essential component in controlling the atmospheric environment of the farrowing house, in that air circulates downwardly through the slots to control the temperature and diffusion of odors.
Known gang slats, such as those discussed above, generally include a slotted central section of reinforced concrete for supporting the sow and the central pen of a farrowing crate thereon, and they also include slotted opposing side sections of reinforced concrete, integral with the central section, for supporting the farrowing crate side pens and the litter of pigs thereon. Most of the slots in the gang slat are relatively narrow, usually being about 3/8 inch (9.53 mm) wide, and thus have presented only a minimal hazard to the safety of the pigs in the litter. However, in order to permit the sow's waste to more readily pass through the gang slat to the pit below, each gang slat, heretofore, has been provided with a group of relatively wider slots in a rear portion of the central section of the gang slat. Such wider slots usually have been about one inch (25.4 mm) wide. It is apparent that the feet and legs of newborn pigs would easily be caught in such relatively wide slots and would result in serious injury or death of the pigs.
In attempting to avoid the problem presented by the relatively wide slots in the gang slat, it has been a common practice for the farmer to temporarily place a mesh grate upon the gang slat and overlying the area of wide slots. Such mesh grate has relatively small openings therein and has served to protectively receive newborn pigs thereon and permit them to walk about thereon without injury to their feet or legs. About three days after the pigs are born, at which time they will have grown sufficiently in size and stability so they are able to maintain their footing on the surface of the gang slat, it is desirable that the mesh grate be removed from the gang slat.
It is apparent that, because the mesh grate overlies substantial solid portions of the gang slat, this results in waste from the pigs and the sow being prevented from passage through the substantial mesh portions of the grate overlying the solid portions of the gang slat. This problem is becoming increasingly significant because it frequently happens that an attendant is reluctant to remove such mesh grates, and instead, leaves them in place and attempts to periodically wash the excess waste from the grates and through the slots in the gang slats. Consequently, excessive amounts of waste tend to accumulate on the grates, especially on those portions of the grates which overlie the solid portions of the gang slat, and on other adjacent areas of the gang slats, and may not be removed until a general cleaning of the entire farrowing crate area may be expected, probably after the sow and the litter of pigs are removed from the respective farrowing crate.